gene pyramiding in tomato for leaf curl, drought and quality characters

1. Gene Pyramiding in Tomato
Speaker : Ms. Rashmi Kumari
PhD (2nd Semester)
Reg. No :- D/HORT/005/BAC/2015-16
Department of Horticulture
(Vegetable & Floriculture)
BIHAR AGRICULTURALUNIVERSITY, SABOUR
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2. What is gene pyramiding ?
Gene pyramiding is defined as a method aimed at assembling multiple desirable
genes from multiple parents into single genotype for specific trait.
Pyramid could be constructed with major gene, minor gene, effective genes,
ineffective genes, race-specific genes, non-race specific genes, or any other types
of host gene that confers resistance.
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3. Why gene pyramiding?
Enhancing trait performance by combining two or more genes.
Remedy of deficits by introgression of genes from other sources.
Increasing the durability of disease resistance.
Broadening the genetic basis of released cultivars.
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4. Types of gene pyramiding
Conventional Technique
Serial gene pyramiding : Genes are deployed in same plant one after one
Molecular technique
Simultaneous gene pyramiding : Genes are deployed at a time in a single plant
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5. (Hospital et al.,2004)
Gene pyramiding scheme cumulating six target genes.
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6. Different schemes of marker-assisted backcrossing for gene pyramiding
RP- Recurrent parent; DP- Donor parent; BC-Backcross;
IRP- Improved recurrent parent.
A. Stepwise transfer;
B. Simultaneous transfer;
C. Simultaneous and stepwise transfer. Joshi and Nayak (2010)
A B C
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7. EFFICIENCY OF GENE PYRAMIDING
 A MAS based gene pyramiding scheme based on a cascading pedigree is less
expensive and requires the smallest cumulated population size of all the schemes. The
average transmission probability is 0.9975.
 Gene pyramiding scheme based on the crosses of founding parents the population size
is somewhat higher. The average transmission probability is 0.9967.
(Hospital et al.,2004)
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8. Effectiveness of marker-assisted backcrossing for gene pyramiding
depends upon
 Distance between the closest markers and the target gene
 Number of target genes to be transferred
 Genetic base of the trait
 Number of individuals that can be analyzed
 Genetic background in which the target gene has to be transferred
 Type of molecular marker used
 Available technical facilities
(Weeden et al., 1992; Francia et al., 2005) 8

9.  Scientific name : Solanum lycopersicum L.
 Chromosome no.: 2n = 2X = 24
 Origin : India
Tomato
Area, Production & Productivity status
In India : (2nd rank)
 Area: 0.882 million hectares
 Production: 18.73 million tonnes
 Productivity: 21.2 MT/ha.
In Bihar : (9th rank)
 Area: 0.047 million hectares
 Production: 1.061million tonnes
 Productivity: 22.3 Mt/ha.
Source: NHB database, 2014 9

10. Pyramiding for ToLCV and its effect on yield &
other associated traits
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11. ToLCV Resistance Sources
S. habrochaites f. glabratum
S. peruvianum
S. peruvianum
S. chilense
Resistant gene sources References
Ty-1 S. chilense Zamir et al., 1994
Ty-2 S. habrochaites f. glabratum Kalloo and Banerjee(1990)
Ty-3 S. chilense Ji et al. (2007)
Ty-4 S. chilense Ji et al.(2009)
Ty-5 S. peruvianum Hutton et al. (2012)
Ty-6 S. chilense Hutton et al. (2012)
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12. ToLCV Disease Severity Index
 DSI =0 No symptoms
 DSI=1 Some symptoms at new growing point but only visible from close distance
 DSI=2 Symptoms are visible from 2 feet but still localized to new growing points
 DSI=3 Symptoms are visible all over the plant
 DSI=4 Symptoms are so severe and plant are stunted and stop growing
(Friedmann et al. 1998, Lapidot and Friedmann 2002)
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13. Pyramiding Ty-2 and Ty-3 for ToLCD
Disease reaction to Tomato leaf curl Bangalore virus (ToLCBV), Tomato leaf curl New Delhi virus (ToLCNDV) and
Tomato leaf curl Palampur virus (ToLCPalV) by pyramided lines and tomato lines differing for presence of Ty genes, 60
days post-agroinoculation. Tomato cultivar Punjab Chhuhara is a susceptible control.
Prasanna et al., 2015
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14. Cont……
Prasanna et al., 2015
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15. Response of pyramided lines and tomato lines carrying different Ty genes
to three different tomato leaf curl virus species in agro-inoculation tests
DSI: disease severity index as described earlier; DPI: days post-inoculation
Prasanna et al., 2015
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16. Horticultural performance and response of pyramided lines and tomato
lines carrying different Ty genes in field traits
Prasanna et al., 2015 16

17. Parent lines used to make a set of non-reciprocal di-allele crosess
Disease severity index means of F1 hybrids and parental lines scored 5 weeks after inoculation with
Tomato yellow leaf curl virus
Vidavski et al. 2008Ten infected plants from each parental line or F1 hybrid were evaluated in each replicate 17

18. Line/F1 hybrid DSI Average yield kg/plant Yield loss (%)
SUS
Non-inoculated
Inoculated
4.0 5.2
0.04
99.2
PIM
Non-inoculated
Inoculated
3.6 8.8
0.9
89.7
CHIL
Non-inoculated
Inoculated
2.6 5.4
2.0
62.9
HAB
Non-inoculated
Inoculated
1.3 4.3
1.4
67.4
72-PER
Non-inoculated
Inoculated
1.3 7.7
3.4
55.8
Vidavski et al. 2008
TyLCV-induced symptom severity and yield reduction of the different parents and F1 hybrids
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19. Line/F1 hybrid DSI Average yield kg/plant Yield loss (%)
SUS×PIM
Non-inoculated
Inoculated
4.0 10.1
0.9
91.1
SUS×CHIL
Non-inoculated
Inoculated
2.7 10.2
1.9
81.4
SUS×HAB
Non-inoculated
Inoculated
2.2 7.7
1.7
77.9
SUS×72-PER
Non-inoculated
Inoculated
3.8 8.7
2.3
73.6
PIM×CHIL
Non-inoculated
Inoculated
1.9 12.2
2.8
77.0
Vidavski et al. 2008
Cont……
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20. Line/F1 hybrid DSI Average yield kg/plant Yield loss (%)
PIM×HAB
Non-inoculated
Inoculated
1.6 11.1
2.7
75.7
PIM×72-PER
Non-inoculated
Inoculated
2.2 11.0
3.8
65.5
CHIL×HAB
Non-inoculated
Inoculated
2.6 7.3
3.0
58.9
CHIL×72-PER
Non-inoculated
Inoculated
2.0 6.9
2.4
65.2
HAB×72-PER
Non-inoculated
Inoculated
0.9 9.3
5.0
46.2
Vidavski et al. 2008
Cont……
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21. Pyramiding for drought and its
effect on yield & quality
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22. Pyramiding of S. pennellii Introgressions
Gur and Zamir (2004)
Effect on yield (fruit weight kg/m2)
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23. Gur and Zamir (2004)
Effect on TSS (%)
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24. Gur and Zamir (2004)
Effect on TSS and yield (Brix/g of fruit)
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25. Pyramiding for quality traits and its effect on yield
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26.  S. pennellii introgression lines have been found to be powerful
material for dissecting plant yield and fruit quality (Gur and Zamir
2004; Rousseaux et al. 2005; Stevens et al.2007).
 S. pennellii introgression lines also used for enhacning carotenoids,
fruit weight and composition in sugars and acids, antioxidant
compounds, volatile aromas and various metabolites (Lippman et al.
2007).
 Introgressions originating from S. pennellii were introduced into lines
of processing tomato, and the resulting hybrid AB2 is presently a
leading variety in California (http://www.ptab.org/ranking9.htm),
which is the largest producer of processing tomatoes in the world.
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27. Pyramiding for fruit quality traits in tomato
Ascorbic acid, total phenols and °Bx content in red-ripe fruit from the tomato IL7-3, IL12-4, ILH7-3, ILH12-4, ILH7-3+12-4,
IL7-3+12-4 genotypes and the parental line M82. Sacco et al.,2013
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28. Effect of gene pyramiding on yield
Sacco et al.,2013 28

29.  Gene pyramiding in tomato is mainly done for TyLCV, drought and quality characters.
 The pyramided tomato lines developed can be important genetic resources for sustainable tomato production
in areas affected by tomato leaf curl virus disease.
 Marker-assisted selection for TyLCV resistance genes offers many advantages, including the possibility of
eliminating susceptible plants in a segregating population before transplanting, and the identification of plants
homozygous for Ty-2 and Ty-3 or other combinations in early generations so that selection in later
generations could focus on horticultural, fruit quality or nutritional traits.
 The combination of multiple wild introgressions is likely to also bring negative horticultural traits caused by
linked genes. Therefore it would be useful to generate and use minimal introgression lines for pyramiding of
different specific genes.
Conclusion
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30. Thank you…
…For your kind attention
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